Calculate the Arc Length- Is this correct?-if so how do you

[ku1005]

Asked to calculate the arc length of y below for 1<=x<=3 ie[1,3], I come up with the integral also below, the only problem i , im not sure how to calculate this integral and thus fear I have made an error, is anyone able to verify my answer/show me a way to calculate it? cheers



PS arc length of a curve is given by

ARC LENGTH = sqrt( 1 + [dy/dx]^2)

 

[morson]

You've derived the integral required.

Your integral can be rewritten as:

\(\displaystyle \L\ \int_{1}^{3} (\frac{1}{2x}\ + \frac{x}{2}\) dx\)

= \(\displaystyle \L\ ( \frac{1}{2}\ln(x) + \frac{x^2}{4}\ )| _{1}^{3}\)

= \(\displaystyle \L\ \frac{1}{4}\(ln(9) + 8)\)

My arithmetic could be a bit off, someone correct me if so.

 

[ku1005]

cheers m8...works a treat